Spider mites are the number one most pesticide resistant crop pest worldwide. It has relatively few predators and is difficult to control. Its genome sequence has been determined recently, and it is much smaller than in its arthropod relatives, but contains an enlarged collection of genes involved in RNA interference (RNAi), a pathway that uses RNA molecules to turn genes on and off. The project will study how these genes work when a mite ingests small RNA when feeding on plants, and whether this system can be used to control gene expression in the animal. The research activities associated with this project will provide training at the graduate and undergraduate level in biochemistry, genetics, and computational biology. It will rely heavily on the involvement of undergraduate researchers, both in the classroom and the laboratory.
The approach of the project involves exploring the ability of naturally occurring plant RNAs to accumulate in spider mites. After being raised on a variety of plants, the identity of plant RNAs entering mite cells will be determined with high throughput sequencing. Next, synthetic RNAs targeted to essential mite genes modeled from accumulating native plant molecules will be fed to mites and their effects on survival and gene expression investigated. RNAs that successfully modulate genes in mites will be characterized biochemically and in cell culture to understand the mechanism they exploit.
